Hello James, I'd say it is no problem at all, unless You really want to replace them all in the main namespace, if there are specific rules and only some should be replaced and others not, it depends on the rules, if these are special enough to program the bot with them.

P.S. Something You should be checking before, would be if these are really valid unicode characters (e.g.) and that these characters are really used that way. You might find this useful (for the fonts). In case of questions about bots #pywikipediabotconnect might be helpful in case of technical questions about WM-projects #wikimedia-techconnect.